Me too, oh wait I did. :D
Facing the bell housing and up at a 45 angle on the inside of the pipe.
After reading a LOT about the A/F sensors and placement I used pipe color to determine where to install the bung.
Different discoloration of the exhaust tubing relates to different temperatures and the sensors like to be within a certain range of exhaust heat to read correctly.
It's not super critical or anything, but if it's a choice it might as well be in a good functional position.
In my system it was right after the collector flange.
